Insert molding is used as a method for decorating a surface of a cubic structure such as three-dimensionally shaped substrate, but a mold must be produced for each product and this method is unsuitable for dealing with various products.
A method of adhering a decoration film or a protective film to a cubic structure such as three-dimensionally shaped substrate can easily respond to various products and is advantageous. In order to successfully and neatly adhere a film to a cubic structure such as three-dimensionally shaped substrate, the film is adhered using a vacuum heat and pressure applicator or the like while heating and extending the film. Therefore, a heat-sensitive adhesive is generally used for the adhesion to an adherend. However, a sufficiently high adhering property cannot be exerted instantaneously after adhesion, and there is a problem in the hot adhering property/hot holding power.
Conventional compositions close to that of the adhesive layer of the present invention include the followings, though these are not technically related to the present invention.
Japanese Patent No. 3516035 (WO 1998/051754) discloses a pressure-sensitive adhesive composition obtained by adding (2) from 1 to 40 parts by weight of an amino group-containing adhesion-enhancing component having a Tg of 40° C. or more and a weight average molecular weight of 100,000 or less to (1) 100 parts by weight of a carboxyl group-containing adhesive component having a weight average molecular weight of 800,000, and this composition when adhered to a plastic exhibits foaming resistance at high temperatures.
Japanese Unexamined Patent Publication (Kohyo) No. 2006-522856 (WO 2004/094549) discloses an optically transparent pressure-sensitive adhesive composition comprising a blend which comprises from 70 to 90 wt % of a pressure-sensitive adhesive component containing at least one polymer having an acid functional group or a base functional group; from 10 to 30 wt % of a high-Tg (20° C. or more) polymer containing an acid functional group or a base functional group and having a weight average molecular weight of 100,000 or more; and a crosslinking agent.
U.S. Pat. No. 4,045,517 discloses a hot-melt adhesive composition comprising:
(A) from 5 to 95 parts by weight of a polymer comprising the following components (1) and (2) and having a glass transition temperature (Tg) of −85 to 0° C.:                (1) from 85 to 99.5 parts by weight of an alkyl acrylate or alkoxyalkyl acrylate having a carbon number of 2 to 18; and        (2) from 0.5 to 15 parts by weight of an ethylenically unsaturated amine, carboxylic acid, sulfonic acid or mixture thereof and        
(B) from 5 to 95 parts by weight of a polymer comprising the following components (3) and (4) and having a Tg of 20 to 150° C.:                (3) from 85 to 99.5 parts by weight of an alkyl, cycloalkyl or isobornyl (meth)acrylate; and        (4) from 0.5 to 15 parts by weight of an ethylenically unsaturated amine, carboxylic acid, sulfonic acid or mixture thereof, wherein either one of (A) and (B) contains an acid group and another one contains an amino group.        
Japanese Unexamined Patent Publication (Kohyo) No. 2005-105256 (WO 2005/023913) proposes a poly(meth)acrylate film composition obtained by blending
(A) a carboxyl group-containing poly(meth)acrylate having a Tg of 0° C. or more, and
(B) a tertiary amino group-containing poly(meth)acrylate having a Tg of 0° C. or less,
or blending
(C) a tertiary amino group-containing poly(meth)acrylate having a Tg of 0° C. or more, and
(D) a carboxyl group-containing poly(meth)acrylate having a Tg of 0° C. or less, wherein (A):(B)=from 10:90 to 90:10 wt % and (C):(D)=from 10:90 to 90:10 wt %.